Stuck on level one

I have seen a comment on another site that indicates what I have also experienced. There appears to be a bug on level one. I have the 'stone desk' and the 'desk with symbol' but neither of the two secret passages open. The passage even has a symbol similar to the 'stone desk' but it does not open.

This is not a bug. There are two stone keys and three symbols in this level. You have to put together the first key from a trash. See this walkthrough:

• examine a mummy near the start point and talk to young digging arab
• pick a stone desk from mummy
• pick a bucket
• pick a flask of oil
• go to pulley station
• put the bucket to pulley station
• use the flask of oil to a crank on pulley station
• turn with the crank
• climb up
• pick the bucket
• use it on sieve
• pick trash
• pick other bucket
• put it on elevator
• use elevetor handle
• pick trash from bucket
• use trash on trash in inventory and use it in inventory menu
• solve puzzle
• talk twise with old arab
• go to car
• pick whiskey and gun
• go to new room
• drink whiskey
• use mathces on stone lamp
• use stone key from trash to stone desk near door
• open sarcophagus
• examine mummy
• pick stone desk
• go back to start point
• talk with young arab
• pick pickaxe
• pick stone desk near elevator
• go to hole opposite to one where is new room
• use pickaxe to wall
• use matches to stone lamp
• use stone desk to stone desk near door
• open sarcofag
• examine mummy
• pick stone desk
• go to start point
• use three stone desks on strongbox
• pick pyramid and stone seal
• go to room where you find flask of oil and search hidden places
• use stone seal on door
• go downstairs

I'm just playing the Demo version I've done and got every thing, and have solved the Trash puzzel but it stays on the screen and nothing happens ? is this the end of Demo ?.

I've got everything from your list down to 25 (use Stone key Key from Trash ?) see above note, Any Idea's , you can pm me at ejp@videotron.ca